Lasd to retest 4,000 DNA samples after using defective tests for 8 months

In August, a manufacturer of DNA test kits sent a letter to the Sheriff’s Department of the County of Los Angeles, warning the managers to stop using certain test kits which had proven to be inclined to give incomplete results.

The letter finally landed in front of a civil employee of the department’s scientific services office – but the employee did not throw the kits or send them back, the sheriff officials announced on Wednesday.

Instead, the ministry continued to use defective kits for an additional six months, testing thousands of samples from a range of criminal cases and surveys.

It was only on Monday that a supervisor of the Scientific Services office discovered the advice of the test company and that the officials achieved what had happened.

Now, the ministry has opened an internal administrative investigation into the incident, as those responsible are faced with the intimidating task of Rettester 4,000 samples and to determine how the imperfect kits may have affected criminal affairs. In some cases, existing samples may be too small to be removed, said the ministry.

“We take the integrity of our criminal surveys and the reliability of our medical-legal tests very seriously,” said Sheriff Robert Luna in a Press release Wednesday afternoon. “The Sheriff department works with diligence to assess the impact and prevent such situations from reproducing.”

The ministry did not provide a copy of the company’s letter and refused to appoint the company. Sheriff managers said that the civilian employee involved in the incident was no longer with the ministry but did not specify why the person left or when.

In total, the ministry used defective kits for eight months from July 2024 to February 2025.

“Based on the information provided by the DNA test kit manufacturer,” said the ministry, “the use of affected kits may have led to incomplete or sub-optimal results, but it is unlikely to have falsely identified a person.”

Los Angeles County Dist. Atty. Nathan Hochman said that his office had started working with the sheriff department to assess the scope of the problem and ensure that people involved – including defendants, victims and the public – are held.

“We will follow the facts in the direction they take us in an individual case and make decisions which are in full compliance with the law on the way of remedying a particular situation which requires such compensation,” he wrote in a press release. “Ensuring the integrity of the criminal justice process to build and maintain confidence in its results is essential as we are advancing.”

Brooke Longuevan, president of the public of the public defenders, described the situation as “deeply worrying”.

“This failure will undoubtedly delay criminal affairs, leaving our customers in detention pending even longer than their trials progress,” she said. “Serious supervisors like this compromise not only the integrity of individual cases, but also public distrust of the criminal legal system and questions the effectiveness and accuracy of criminal surveys.”